Cleaning torch



Aug. 11, L, M, HOESE 'ET AL CLEANING TORCH Filed March 13, 1957 2Sheets-Sheet 1 1 22 INVENTORS Zeroy Al. 1 /0656 BY flz'ke .rl. Wren Aug.11, 1959 Filed March 13, 1957 L. M. HOESE ET AL CLEANING TORCH 2Sheets-Sheet 2 INVENTORS (Xe/"0g J6. 370656 By Mike A. 37Z7z CLEANINGTORCH Leroy M. Hoese and Mike A. Trtan, Granite City, 111., assignors toAmerican Steel Foundries, Chicago, 111., a corporation of IllinoisApplication March 13, 1957, Serial No. 645,838

Claims. (Cl. 219-70) This invention relates to a gun such as is commonlyused to hold a carbon electrode and to apply the electrode to aworkpiece which is flame washed by an electrical are struck between theworkpiece and the electrode in the presence of a stream of compressedair directed by the gun along the electrode to the arc.

Prior art guns commonly used for this purpose have been notoriouslyunsatisfactory due to their lack of maneuverability and short servicelife.

A primary disadvantage of such prior art guns has been the necessity fora heavy electrical cable adequate to conduct the necessary electricalcurrent. Another disadvantage has been bulky construction to provide airpassages which are necessary to accommodate flow of air from the gun tothe electrode.

Another disadvantage of prior art guns has been their lack ofmaneuverability due to the fact that in certain positions they areeffective only when the electrode is moved in one direction along aworkpiece. Another disadvantage is the impossibility of working incorners with a short electrode.

Still another disadvantage of prior art guns has been their short lifein service as a result of the great heat developed in the electrode andthe gun during flame washing of castings in a production line as, forexample, in the finishing of steel castings.

Accordingly, a primary object of the invention is to devise a gun whichis compact and light weight in construction and which accommodates anelectrical cable of minimum weight.

Another object of the invention is to direct a stream of air along bothsides of the electrode so that the electrode may be moved in bothdirections horizontally and vertically when the gun is held in aposition whereat the longitudinal axis of the electrode defines a planewhich is approximately vertical.

Still another object of the invention is to offset the noses of the gunjaws which carry the electrode positioners and to arrange suchpositioners so that the operator may conveniently flame wash the cornersof large castings even with a short electrode.

Yet another object of the invention is to minimize the transmission ofheat from the electrode to its positioners and thence to the jaws of thegun. This object is accomplished by providing the positioners with novelelectrode gripping surfaces and means for cooling the surfacespreferably at their points of contact with the electrode.

The foregoing and other objects and advantages of the invention willbecome apparent from a consideration of the following specification andthe accompanying drawings, wherein:

Figure l is a perspective view of a gun embodying a preferred form ofthe invention;

Figure 2 is a side elevational view of the gun with the handle shownfragmentarily and in section;

Figure 3 is an end elevational view taken from the line 33 of Figure 2;

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Figure 4 is a bottom plan view of the structure shown in Figure 2;

Figure 5 is a plan view of one of the electrode holders;

Figure 6 is an elevational view of the holder shown in Figure 5;

Figure 7 is a sectional view on the line 7-7 of Figure 5 with theelectrode in engagement with the positioner, and

Figure 8 is a side elevational view partly in section of the electrodecable shown in Figure 1.

Describing the invention in detail and referring first to Figures 1 and2, it will be seen that the novel gun comprises top and bottom jaws 2and 4 having noses 6 and 8, respectively, offset or angularly related tothe longitudinal center line x-x (Figure 4) of the gun. The noses 6 and8 carry electrode positioners 10, one of which is illustrated in detailin Figures 5 to 7 wherein it will be seen that the novel positioners aresubstantially round as seen in the plan view of Figure 5 and each isprovided with a fiat 12, intersected by blower ports 14 adapted todirect a stream of compressed air along an electrode 16 to an are whichis between the electrode and an associated workpiece (not shown).

The electrode 16 is ordinarily round in cross-section as shown in Figure7 and sets against a V-shaped surface 18 of each positioner 10. Thus theelectrode is substantially in line contact with the holders 10 so thattransmission of heat from the electrode to the holders is minimized asdistinguished from prior art arrangements wherein frequent replacementof positioners and repair of their supporting jaws has presented aserious problem in the art. Also as best shown in Figure 7, the novelpositioner 10 is provided with ports 20 interrupting the V-shapedsurface 18 and formed and arranged to direct a stream of air against theelectrode 16 preferably at points along its line contact with thesurface 18. It has been found that the cooling action of compressed airthus directed against the electrode 16 has been unusually eiiective toreduce damage to the holders and the jaws.

The ports 20 are preferably substantially smaller in diameter than theports 14 because it has been found that the relatively smallercross-sectional area of the port 20 functions as a throttle maintainingadequate back pressure to aiford an adequate stream of air from theports 14 along the electrode 16. This throttling action, however,permits adequate flow of cool air through the ports 20 to preventexcessive heating of the holder 10.

The ports 14 and 20 of the holder 10 are connected to an annular airchamber 22 in the form of an annular groove or recess in a fiat surface24 of the holder which snugly engages the related jaw in substantiallyair-tight engagement therewith. A screw 26 extends through an opening ofeach jaw and is threaded into a stud 28 (Figures 6 and 7) tofrictionally clamp the surface 24 of the holder against a complementaryflat surface of the jaw thereby maintaining the substantially air-tightcon tact therebetween and permitting rotation of the holder 10 about itsstud as may be desired by the operator. Such rotation may beaccomplished, for example, by pushing the tip of the electrode so thatthe holders rotate to position the electrode at the angle desired by theoperator.

The top jaw 2 may be integral with or attached as by silver solder to alug 30 on a handle 32 and to a hinge lug 34, and the jaw 2 comprises anair passage 36 extending from the rear extremity of the jaw to a port 38therein, said port communicating with the annular passage 22 of therelated holder 10.

The lower jaw 4 may be integral with or fixedly attached as by silversolder to a handle support 40 having a pair of hinge lugs 42 whichreceive the hinge lug 34 therebetween and are pivoted or hinged theretoas by a pin or rivet 44. The nose 8 of the lower jaw comprises an airpassage 46 having a port 48 connected to the annular chamber 22 of therelated holder 10. The passage 46 is also connected to a slotted groove50 in the bottom of the handle support 46 which may be integral with thelower jaw 4 or attached thereto as above mentioned by solder or othersuitable means to seal the connection between the support 40 and thelower jaw 4 around the perimeter of the groove 50. The groove 50 isconnected at its rear extremity to an air passage 52 of the support 40and the passage 52 is in turn connected to a threaded socket 54 formedin a boss or lug 56 of the support 40 at its rear extremity. The socket54 is adapted to receive a threaded pipe nipple 58 in threadedengagement therewith, said nipple being attached by a clamp 60' to ahose 62. The hose is also attached by a clamp 64 to a pipe coupling 66having a connector 68 for convenient attachment to a source ofcompressed gas, such as, for example, compressed air which flows throughthe coupling 66 into a passage '72 of a cable fitting 74, which ispreferably formed as part of the coupling 66. The compressed air flowsfrom the passage 72 through ports 76 of the fitting 74 and thencethrough hose 62 and the ports 78 of a fitting 80 having an air passage82 connected to the port 78 to convey air therefrom through the nipple58 from which the air flows into the before mentioned passage 52 andgroove 50. The grooves 50 is connected by a conduit 34 such as a sectionof copper tubing to a flexible rubber hose 86 which is in turn connectedto another conduit 88 such as a section of copper tubing which isconnected to the before mentioned air passage 36 in the top jaw 2. Thusair delivered to the hose 62 from the coupling 66 is delivered to theair chambers 22 of both electrode holders It) for the purposesheretofore described.

The fittings 74 and 80 within the hose 62 are connected in anyconventional manner, as by soldering, to an electrical cable 90 (Figure8) which afiords an electrical connection between the connector 63 andthe support 40 which is electrically connected to both the top andbottom jaws 2 and 4 which are electrically connected by means of theelectrode holders 10 to the electrode 16.

The jaws 2 and 4 are preferably biased to closed position as, forexample, by means of a conventional compression spring unit 92 which iscompressible by and between the handle 32 and the handle support 40, asbest seen in Figure 2.

The insulated handle 94 (Figure 1) is in the form of a sleeve and isslidably fitted over the bosses 56 and is snugly seated against lugs 96thereof to define an air space within the handle 94 around the boss 56.The handle is attached in any convenient manner, as for example, by ascrew 98 (Figure 2) received within a threaded opening 100 (Figure 4) ina lug 102 of the boss 56.

The handle 32, as well as the top and bottom jaws 2 and 4, includingtheir noses 6 and S, is preferably covered by complementary sections ofinsulation 104- as best seen in Figure 1. This insulation may be securedin any desired manner as, for example, by screws covered with sealingwax.

It should be emphasized that the noses 6 and 3 of the top and bottomjaws 2 and 4 are offset or angled from the longitudinal center line xx(Figure 4) of the novel gun. In actual practice it has been found thatan angle of from about 30 to 45 degrees greatly facilitates the work ofthe operator, particularly with a short electrode. In this connection ithas also been discovered that the distance between the end of each noseand its point of connection to the related jaw, as indicated by A inFigure 4, is preferably greater than the length of the electrodecontacting surface 18 of the holder 10. The best results have beenobtained when the distance A is greater than twice the length of thesurface 18. For example, with a 30 degree offset it has been found thatthe distance A is preferably about 2 /2 inches with the holder having a1% inch diameter; and with a 45 degrees offset the distance A ispreferably about 3% inches with a 1%; inch diameter holder.

Thus it will be understood that the novel gun is compact, economical andlight weight in construction and has greater maneuverability than priorart guns. Moreover, the service life of the holders 10 and the jaws 2and 4 of the novel gun is much greater than any such prior art device.

We claim:

1. A gun of the class described comprising hinged jaws with eachcomprising an electrode holder and a related gripping surface, and aport in at least one of said holders to direct compressed gas along anassociated electrode in contact therewith in a stream approximatelyparallel to its longitudinal axis, said holder having another'portintersecting said surface to direct said gas against contacting surfacesof the electrode and holder.

,2. A gun of the class described comprising V-shaped jaws havingelectrode holders with mutually facing electrode contacting surfaces, anassociated electrode substantially in line contact with said surfaces, aport in at least one of said holders interrupting its electrodecontacting surface to direct a stream of compressed gas against saidassociated electrode at points along the line of contact between saidelectrode and surfaces, and another port connected to the firstmentioned port, said other port opening at one side of said surface andformed and arranged to direct a stream of compressed gas along theelectrode.

3. A gun of the class described comprising jaws having electrodeholders, at least one of said holders having a substantially V-shapedelectrode gripping surface, ports interrupting said surfaces at oppositesides thereof to direct a compressed gas against an associatedelectrode, and another port connected to the first mentioned port andopening at one side of said surface to direct a stream of said gas alongthe electrode substantially parallel to its longitudinal axis.

4. A gun of the class described comprising jaws having electrodeholders, at least one of said holders having a V-shaped electrodeengaging surface and having a flat area approximately normal to saidsurface at one end thereof, ports interconnected with each other andintersecting the surface and rear of said holders, respectively, andmeans for delivering a compressed gas to said ports.

5. A gun of the class described comprising jaws having mutually facingelectrode clamping surfaces in contact with an associated electrodelocated therebetween, means associated with said jaws for clamping saidsurfaces against said electrode, ports at corresponding ends of saidholders for directing a stream of gas adjacent and substantiallyparallel to said electrode, at least one port in each of said holdersinterconnected with said ports, said one port intersecting the clampingsurface of the related holder to accommodate a flow of gas directlyagainst the electrode whereby transmission of heat from the electrode tothe holder is minimized.

6. A gun of the class described comprising jaws having electrode holderswith mutually facing electrode clamping surfaces, means associated withsaid jaws for clamping said surfaces against an electrode, ports in saidholders at corresponding ends thereof to direct a stream of gassubstantially parallel to the electrode towards the end of the electroderemote from the holders, other ports interconnected withthefirst-mentioned ports, said other ports intersecting the clampingsurfaces of the holders to direct a stream of said gas against saidelectrode intermediate said holders, said last-mentioned ports being ofsmaller cross-sectional area than the other ports, and means to deliversaid gas to said ports.

7. A gun of the class described comprising hinged jaws havingsubstantially parallel noses offset at least about 30 degrees from thelongitudinal center line of said jaws, holders at the ends of said nosesremote from said jaws, said holders having mutually facing electrodecontacting surfaces, a port in at least one holder intersecting aportion thereof at one end of its surface to direct a stream ofcompressed gas along an associated electrode, an annular chamber in eachof said holders, said port being connected to said chamber, another portconnected to said chamber, said other port intersecting the relatedcontacting surface to thereby direct a stream of gas at the perimeter ofan associated electrode, and means for delivering said gas to saidchamber.

8. A gun according to claim 7, wherein the distance from the free end ofeach nose to its point of connection with its related jaw is greaterthan the length of the electrode contacting surface of the holdercarried by said nose.

9. A gun of the class described comprising jaws having mutually facingelectrode gripping surfaces in line contact with an associatedelectrode, an air passage extending through one of said jaws and open atone end of its surface to direct a stream of compressed gas along saidassociated electrode clamped by said surfaces, another air passageextending through said one jaw and being interconnected with said onepassage, said other passage intersecting the related gripping surface ata point along the line of contact between said jaw and electrode, aflexible conduit detachably connected to said passage for deliveringsaid gas thereto, and a flexible electrical connector extending throughthe conduit and having an electrical connection to said jaw.

10. A gun of the class described comprising hinged jaws, electrodeholders carried by respective jaws and having mutually facing electrodegripping surfaces, air passages through respective jaws, ports inrespective holders connected to the related air passages and opening atone end of their respective surfaces to direct streams of compressed gasalong an associated electrode clamped by said surfaces, a flexibleconduit interconnecting the air passages of respective jaws and meansfor delivering said gas to one of said passages.

References Cited in the file of this patent UNITED STATES PATENTS2,706,236 Stepath et al. Apr. 12, 1955 2,751,482 Stepath June 19, 19562,764,669 Jones Sept. 20, 1956 2,784,293 Adams Mar. 5, 1957

